Please provide the following information:
1. dotConnect for Oracle version;
2. Oracle Server version;
3. Oracle server bitness (x86 or x64);
4. Which result do you get if you execute the following query against your Oracle Server?

Please make sure that you specify valid values for the "User Id" and "Password" parameters in both connection strings. If a user requires sysdba privileges, for example, the sys user, you need to add "connect mode=sysdba" to the connection string.

I have tripled checked the UserID and Password everything is correct. We also created a POC using generic .net application to connect to the server and DB and are able to connect to it.
After some digging through the forums this issue was already reported and some suggestions were made regarding DB setting we tried all listed and still does not resolve.viewtopic.php?f=1&t=35082&start=15

Try to connect with dotConnect for Oracle in the OCI mode. Is the issue reproduced in this case?

Please also try installing dotConnect for Oracle 9.2.205 or an earlier version. dotConnect for Oracle Trial 9.2.205 can be downloaded by the following link: http://devart.com/pub/dcoracle92205.exe. Can you establish a direct mode connection with this version?